Automatic electric toaster and the like



EDec. 5, 1950 A. POQLE ETAL fi fi AUTOMATIC ELECTRIC TOASTER AND THELIKE Filed Jan. 29, 1948 2 Sheets-Sheet 1 Dec. 5, 1958 A. POOLE ETAL i253.;. 56

AUTOMATIC ELECTRIC TOASTER AND THE LIKE Filed Jan. 29, 1948 2Sheets-Sheet 2 CURRENT SUPPLY 1 m 83 W "\/V\/\/ Patented Dec. 5, 1950UNITED STATES PATENT OFFICE AUTOMATIC ELECTRIC TOASTER AND THE LIKEApplication January 29, 1948, Serial No. 4,988

2 Claims. 1 v The present invention relates to improvements in toastersand the like and relates more particularly to improvements in toastersand the like which are electrically heated and controlled by anautomatic timing-device.

One of the objects of the present invention is to provide a superiorautomatic electricallyheated toaster or the like having a timing-devicegoverning the duration of the heating cycle, and which is provided withsimple and reliable means whereby the efiectiveness of the timing-deviceis delayed until such time as the toaster or the like has reachedsubstantially its normal operating temperature.

Another object of the present invention is to provide a toaster or thelike of the general character above referred to and having simple,reliable and effective means whereby .when the toaster or the like isfirst put into operation (cold start), the eiiectiveness of its initialheating cycle will not be materially difierent from the effectiveness ofsubsequent heating cycles (hot start).

A further object of the present invention is to provide a superiorautomatic electrically-heated toaster or the like having a timing-devicefor governing the duration of the heating cycle, together with simpleand reliable means whereby the start of the timing cycle of the saidtimingdevice will be delayed until such time as the toaster or the likehas reached substantially its normal operating temperature, to therebyprovide heating cycles which are substantially uniform.

Still another object of the present invention is to provide a superiortoaster or the like of the general character referred to, in which asynchronous electric motor-drive is employed for the timing-device, inconjunction with a heat-distortable member constructed and arranged todelay the effectiveness of the timing-device, for the purposesdescribed, and which heat-distor able member is heated by currentflowing directly therethrough to the heating-means.

A further object of the present invention is to provide a superiortoaster or the like of the character above referred to and having asynchronous electric drive-motor for its timing-device, together withthe heat-distortable means above referred to, and having the parts soconstructed and arranged that the energizing-coil of the synchronouselectric motor may be formed of con-- ductors of sufficient diameter andruggedness towithstand not only rough handling but the ravages ofexpansion and contraction due to heating and cooling of the apparatus.

With the above and other objects in view, as

.will appear to those skilled in the art from the present disclosure,this invention includes all features in the said disclosure which arenovel over the prior art.

In the accompanying drawings, in which certain modes of carrying out thepresent invention are shown for illustrative purposes:

Fig. 1 is a schematic view in side elevation of an automatic electrictoaster embodying the present invention but shown with the housingomitted for clarity of illustration;

Fig. 2 is a view thereof in front elevation;

Fig. 3 is a view in front elevation of the electrically-controlledtiming-device shown with the cover removed and the front movement-platepartly broken away;

Fig. 4 is a broken sectional view taken on the line l4 of Fig. 3;

Fig. 5 is a detached perspective view of the unit comprising thefourth-arbor, fourth-pinion, third-gear and retarding-disk, with thesaid third-gear partly broken away;

Fig. 6 is a perspective View of the unit com- ,prising the adjusting-armand bimetallic retarding-member;

Fig. '7 is a transverse sectional view taken on the line l--l of Fig. 6;and

Fig. 8 is a diagrammatic View schematically illustrating the circuitrelationships of the heating-coils, synchronous electric motor,retarding member and electric switch.

The particular automatic electric toaster herein chosen for purposes ofillustrating a preferred form of the present invention, includes a base30 preferably formed of insulating material, and three parallelspaced-apart vertical plates arranged crosswise of the said base Ill andrespectively designated as a front plate ii, an intermediate plate l2and a rear plate It. The plates l2 and I3 are connected together attheir respective upper and lower ends by tie-bars l4 and i5, of whichthere are three of each.

Secured to each pair of aligned tie-bars l and i5 is one of threeparallel coil-holding plates IS, ll and I8, preferabl formed of mica orother suitable heat-resistant insulating material. Each of the saidcoil-holding plates !6, I! and 18 above referred to supports and isencircled by one of three heating-coils l9, 29 and 2| which arediagrammatically illustrated in Fig. '7.

Extending upwardly from the base ill at a point intermediate the frontand intermediate plates H and I2, is a vertical guide-post 22 (Fig. 1)upon which is mounted with capacity for reciprocation, a foodortoast-holder 23 which, in a manner well understood in the art, extendsinto the spaces between the adjacent ones of the coilholding plates [6,l1 and 18 to support slices of bread or other food. The toast-holder 23is urged upwardly by a helical elevating-spring 24 encircling the lowerportion of the guide-post 22 in a position intermediate the base I andthe underside of the said toast-holder 23.

The toast-holder 23 is provided with a for.-

wardly-extending operating-arm 25 which ex- =1 tends through and isadapted to move vertically in a vertical clearance-slot 26 formed in thecentral portion of the front plate ill- At its extreme forward end, thesaid operating-arm 25' is provided with an operating-button orfinger-piece 21, by means of which the toast-holder 23 may be depressedagainst the tension of the elevatingspring 24, in a manner common in theart.

The operating-arm 25 of the toast-holder 23- is formed with a dependinglatching-hook 28 (Figs. 1 and 2) which is adapted to be hooked under aretirable latching-hook .29- formed upon the upper portion of a pivotallatching-lever 30 which is pivoted intermediate its upper and lower endsto the front face of the front plate II. by means of a stud 3 I. Thesaid latching-lever is urged to turn in a clockwise direction (as viewedin Fig. 2) by a latch-spring 32 and is liimted in the turning movementjust referred to by a stop-finger 33 projecting forwardly from the frontplate H.

The upper side edge of the latching-lever 39 is bent forwardly in aninclined plane to provide a releasing-flange 34 which is adapted to haveits underface engagedby an actuating-roller 35. turning movement on theouter end of an actuating-arm 35 projecting outwardly from atiming-device generally designated by the reference character 31 andmounted against the front of the front plate II before referred to. Thetiming-device 31 may be of any approved design, but in the instanceshown corresponds basically to the timing-device shown and described inU. S. Patent No. 2,359,580 dated October 3.1944 and,

hence, does not require a completely detailed description. The saidtiming-device is illustrated in Figs. 1 and 2 as being substantiallyenclosed within a housing 38, which housing, however, is shown asremoved in Figs. 3' and 8.

The said timing-device 31 includes a synchronous electric motorgenerally designated-by the reference character 39 and is, in effect, amagneto-electric timing-motor; The said motor includes a statororfield-frame 40 having an energizing-coil 4! of relatively-few turns andrelatively-coarse wire such, for instance, as 18 turns of No. 14 wiretotaling about 5'7 inches in length. Located within the zone defined bythe polesalients of the stator-frame 40 is a rotor 42 mounted upon adrive-shaft or first-arbor 43 journaled in any suitable manner at itsrespective opposite ends in a front movement plate 44 and a rearmovement-plate 45. The said movementplates are held in spacedrelationship with respect to each other by a suitable number of pillars46, indicated in Figs. 1 and 3.

The first-arbor 43, in addition to rigidly mounting the rotor 42,rigidly carries a driveor first-pinion 41 which meshes into and drives afirst-gear 48 rigidly mounted upon a second-arbor 49 which may besuitably supported in the movemerit-plates 44' and, 45. The saidsecond-arbor rigidly carries a second-pinion. 50 which, in turn, meshesinto and drives a second-gear 5|. The

said second-gear is rigidlymounted upon. a thir The saidactuating-roller is mounted for arbor 52 which also has rigidly mountedupon it a third-pinion 53, all as indicated in Fig. 3.

The third-pinion 53 above referred to meshes into and drives athird-gear 54 which is rigidly mounted upon a fourth-arbor 55. The saidfourth-arbor also rigidly carries a fourth-pinion 56 which meshes intoand drives a fourth-gear 51. The said fourth-gear is rigidly mountedupon a fifth-arbor 58 which, like the other arbors, may be convenientlysupported in the movement plates 44 and 45.

The fifth-arbor 58 above referred to also carries, but with freedom forrelative rotation with respect thereto, a unit which comprises aratchet-wheel 59 and a fifth-pinion 50 rigid with the saidratchet-wheel. On its face adjacent the ratchet-wheel 59, thefourth-gear 51 has pivoted thereto a pawl Bl, the free end of which isyieldingly urged into engagement with the teeth of the ratchet-wheel 59by a pawl-spring 62 also carried by the fourth-gear 51. By means of thepawl 61, the ratchet-wheel 59 and the fifth-pinion 60. are preventedfrom turning in a clockwise direction (Fig. 3) with respect to thefourth-gear 51. It may here be noted that under the particuiarcircumstances as viewed in Fig. 3, the fourthgear 51 is turned by therotor 42 in a clockwise direction, while the ratchet-wheel 59 isnormally urged to turn in the same direction by means of atorsion-spring 53, in a manner as will be hereinafter described.

The fifth-pinion 50 above referred to meshes into and drives afifth-gear 64 rigidly mounted upon a sixth-arbor B5 journaled in themovement-plates 44 and 45. Also rigidly mounted upon the sixth-arbor 65is a, sixthor timingpinion 65 which is adapted to be meshed into b atiming-rack 51 The lower end of the timing-rack 51 above re ferred to isstaked or otherwise rigidly attached to one end of a hub 58 which ismounted for turning movement upon a shaft 69", as is par ticularly wellshown in Fig. 4. The said shaft is supported at its respective oppositeends in the movement-plates M and 55. Mounted adjacent to. andconcentric with the timing-rack 61 is the actuating-lever 35 beforedescribed, which is staked at its inner end to a hub 10, which latter isalso mounted for turning movement upon the shaft 69.

The timing-rack 61 has laterally projecting from it toward theactuating-lever 36 and over the edge thereof, a limiting-stud H which isnormally held in engagement with the adjacent edge of theactuating-lever 36 by means of a helical torsion-spring 12 encirclingthe hub 58. The said torsion-spring has one end hooked around the loweredge of the actuating-lever 35 and has its opposite end hooked aroundthe limiting-stud H, as is indicated in Fig. 3. The said limitingstud llof the timing-rack 61 is adapted to en.- gage with and be stopped by theupper edge of an interval-adjusting rack 13 which has its inner endstaked or otherwise rigidly secured to a hub 14 (Fig. 4) mounted forturning movement upon the shaft 69 before referred to.

The interval-adjusting rack 13 is adapted to be turned into variouspositions of adjustment by means of a setting-pinion 15 rigidly mountedupon a setting-arbor 15 journaled in the movement-plates 44 and 45.

The actuating-lever $6 is yieldingly urged to turn in a clockwisedirection (as viewed in Fig. 3) by means of the torsion-spring as beforereferred to. The said torsion-spring encircles the hub carrying theactuating-lever 36 and having one end hooked beneath the lower edge ofthe said actuating-lever and having its opposite end hooked around theadjacent one of the pillars 46.

As thus constructed and arranged, the torsion spring l2 normally servesto hold the limiting-stud ii in engagement with the upper edge of theactuating-lever for concurrent movement therewith, though providing ayielding connection which will permit the said actuatinglever to beturned in a counterclockwise direction relative to the timing-rack 5?.The torsionspring 63 exerts a constant effort to swing theactuating-lever 35 in a clockwise direction and hence also acts throughthe limiting-stud '5! to tend to swing the timing-rack 81 also in thesame direction.

The torsion-spring 63 acting through the actuating-lever 36,limiting-stud H and timingrack 61, tends to turn the timing-pinion 65 ina counterclockwise direction (as viewed in Fig. 3) and hence through thevarious gears, pinions, etc., exerts some slight but inefiective eifortto turn the rotor 42, which latter, however, chroncusly turning and actsin effect as a governor.

The fourth-arbor before described, in addition to rigidly carrying thethird-wheel and fourth-pinion 56, also rigidly carries a retardingdiskor retarding-member 1! having a substantially-radial retarding-face T8and located be tween the movement-plates 4d and G5.

The retarding-face '13 of the stop-disk U is adapted to engage with aretarding-plate l8 preferably formed of insulating material and rigidlymounted upon a finger 8t, bent at substantially a right angle from oneend of a heatdistortabe retarding-member generally designated by thereference character 8! and in the present instance formed of bimetallicmaterial. The material from which the bimetallic retarding-member 3| maybe made varies widely and requires no detailed description herein otherthan to say that its two layers of welded-together metal arerespectively of different heat-expansion characteristics, as is wellknown in the art, such that when heated, the member will distort, forinstance, into the position in which it is in dicated by broken lines inFig. 3.

The end of the retarding-member 8| opposite its finger 83 is split toprovide two laterallyspaced-apart arms 32 and 83 which are bothmechanically and electrically integrally connected at the end of theretarding-member adjacent its said. finger 89, all as is especially wellindicated in Fig. 6.

The free ends of the arms 82 and 83 of the retarding-member 8| areinsulated from and rigidly secured by means of rivets at or the like toa finger 85 integral with and extending forwardly from a sheet metaladjusting-member generally designated by the reference character 8%. Atits end adjacent its finger the adjusting-member 85 is pivotallyconnected to the forward face of the rearmovement-plate 45 by means of astud 3'1, as is indicated in Fig. 3. At its opposite end, theadjusting-member 38 is formed with a slot 88 through which extends aclamping-screw 89 threaded into the rear movement-plate 45, as is alsoindicated in Fig. 3.

Extending laterally from the operatingarm 25 of the toast-holder '23, isa stud so carrying at its outer end a roller 9| (Fig. 2) preferablyformed of insulating material. The said roller is syn- 9| is adapted,when the toast-holder 23 is depressed, to engage with and downwardlyflex the upper reach of a flexible contact-carrier 92, which at itslower end is rigidly attached to but insulated from a bracket 93 forminga feature of the front plate The contact-carrier 92 carries on theunderface of its free end a contact 94 which is adapted to engage with acomelemental contact '555 secured to the upper face of the free end of asecond spring-like contactcarrier 96, as is indicated in Figs. 2 and 8.Like the contact-carrier 92, the contact-carrier 56 is rigidly attachedto but insulated from the bracket 93 before referred to.

The contact-carrier 92 and, hence, the contact 94, is connected by meansof a wire 91 to the end of the arm 82 of the retarding-member 8|. Thecompanion or complemental arm 83 of the said retarding-member isconnected by means of a wire 98 to one end of the energizing-coil 4|, asis best indicated in Fig. 8. The wire as just referred to may be formedintegral with the said energizing-coil, if desired. The opposite end ofthe energizing-coil 4! is connected by means of a wire 89 to oneterminal of each of the three heating-coils I9, 26 and 2|. The oppositeterminals of the said heating-coils are jointly connected by means of awire M8 to a line-wire IEH, which latter, in conjunction with acomplemental line-wire i212, leads from any suitable source ofalternating current, such for instance as 60- cycle ll5-volt alternatingcurrent. The linewire is: is connected by means of a wire I03 to thecontact-carrier 96 and, hence, to the contact of the latter. Thus, theswitch (formed by the contacts 94 and 95), the energizing-coil 5|,retarding-member BI and the heating-coils are in series.

Operation For the purpose of making clear the operation of theparticular electrically-heated and electrically-timed automatic toastershown in the accompanying drawings, let it be assumed that the toasteris cold and that it is desired to start it operation.

Under the circumstances above described, the toast-holder 23 may bedepressed by means of the finger-piece 2'! thereof until thelatchinghcok 28 thereof is engaged with he latchinghook 29 of thelatching-lever. The described downward movem nt of the toast-holder 23will also depress the actuating-lever of the timingdevice intosubstantially the position in which it is shown by full lines in Fig. 3,and also cause the roller 8! carried by the said toast-holder to flexthe contact-carrier 92 so as to engage the contact 94 thereof with thecontact 95. This will complete a series electrical circuit through theretarding-member 8|, through the energizing-coil 4! of thesynchronous-electric motor 3 3 and thence through the heating-coils it,20 and 2!. As thus constructed and arranged, the curmember 8! and theenergizing-coil il, since the said elements are in series.

By way of example, it may be assumed that the resistance of the circuitthrough the two arms 82 and 83 of the retarding-member 8| meets with aresistance of about (LO-ii ohm; similarly, let it be assumed that theresistance of the energizing-coil 4| is 0.012 ohm. Thus, assuming thatthe resistance ofifered by the heating-coils i9, 28 and 2! to passage ofcurrent between the wires 99 and I00 is about 10.447 ohms,

l itjwiil be apparent that the entire series circuit has a totalresistance of about 10.5 ohms so that, takeneither singly or together,the retarding-member st and the energizing-coil 54 have a resistancewhich is but a small percentage of the resistance oiifered by theheating-coils i9, 2'6 and 2!.

Under the circumstances now being described, the retardingmember 8i willbe cold and, hence, in the position in which it is shown by full linesin-Fig. 3, so that the timing-device will not be able to start thetiming cycle until such time as the said retarding-member has itselfbecome heated by the passage of current directly therethrough.

The passage of current through the heatdistortable,retarding-member 8iwill heat the same and cause it to ultimately flex into the retiredposition in which it is indicated by broken lines in Fig. 3 to therebyremove its retardingplate 13 out of the path of movement of theretarding-face of the retarding-disk ll. This retirement, however, willnot be so far completed as to free the timing-device until theheatingcoils l9, 2% and El and the adjacent portions of the toaster havereached their normal operating temperatures.

As soon as the retarding-member 81 has retired, the synchronous-electricmotor 39 or its equivalent will be free to start the timing cycle whichit will now do. The timing cycle will endure until such time as thetiming-rack El has moved in a clockwise direction sufficiently todisengage its teeth from the timing-pinion '66. When the latter actionoccurs, the actuatinglever 36 willsnap upwardly and engage itsactuating-roller with the underface of the inclined releasing-flange 34of the latching-lever 35*, to swing the latter in a counterclockwisedirection. The counterclockwise swinging movement of the latching-lever36 will cause the retirement of its latching-hook 29 out of engagementwith the latching-hook 28 of the toast-holder 23, thereby releasing thesaid toast-holder and the parts carried thereby for upward movementunder the urge of the elevating-spring 26. The upward movement of thetoast-holder 23 will aiso retire the roller 9! carried thereby andpermit the inherent tension of the contact-carrier 82 to assert itselfand separate the upper contact 94 from the lower contact 85.

The separation of the contacts as just above described, will effect thesimultaneous cessation of current supply to the energizing coil an 'ofthe synchronous-electric motor 39, the arms 82 and 83 of theretarding-member 8i and the heatingcoils i9, 28 and 2|.

Usually in the use of a toaster, it will be utilized for a second timealmost immediately, so

that normally the timing-element will not have time to cool and, hence,the synchronous-electric motor 3Q will be able to function thetimingdevice promptly for the next succeeding cycle. Should, however,the entire toaster cool down from a period of idleness, theheat-distortable retarding-member 3! will reassume the position in whichit is shown by full lines in Figs. 3 and 8 and thereby preclude theoperation of the timingdevice, in its effort to ultimately break thecircuit, until such time as the said retarding-member has again becomeheated and, hence, also the heating-coils i9, 28 and 2! have also becomeheated to function in a normal manner.

The responsiveness of the retarding-member 8| or its equivalent. to heatis preferably so proportioned as to not flex into its full-clearanceposition (broken line position indicated in Fig. 3) until such time asthe'heating-c-oils i6, 28 and 2! and the adjacent parts of the toasterhave also become fully heated to normal operating temperatures. In thismanner, the toaster or its equivalent is caused to function from a coldcondition in substantially the same way it will func tion for each cyclesubsequent to its initial cycle to thus produce a uniform toast or thelike.

By passing current directly through the heatdistortable retarding-memberin order for such current to reach the heating-coils (and in the presentinstance also in order to reach the energizing-coil ll separateheating-coils for a thermostatic element are not required and the saidretarding-member may be mounted directly to the timing-device to operatedirectly thereon, without requiring the complex and troublesome linkagesand the separate heating-coils previously employed.

The point at which the retarding-member 8! will flex s-ufiiciently todisengage from the retarding-disk ll, may be adjusted by swinging theadjusting-member 86 about its stud 8i and looking it in a chosenposition by means of the clamping-screw as.

The invention may be carried out in other specific ways than thoseherein set forth without departing from the spirit and essentialcharacteristics of the invention, and the present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

We claim:

1. An electrically-heated and electrically-timed automatic toaster orthe like, including in combination: a food-holder; electricheating-means located adjacent the said food-holder for heating thecontents thereof; an electric switch controlling the supply of currentto the said electric heating-means; a unitary timing-device forcontrolling the said electric switch and including a frame, asynchronous electric motor carried by the said frame; actuating-meansfor the said electric switch and also carried by the said frame, agear-train opcratively connecting the said synchronous electric motor tothe said actuatingmeans, a movable adjusting-member carried by the saidframe the said gear-train, and a heat-distortable retarding-membercarried by the said adjustingmernber and movable therewith as well aswith respect thereto and constructed and arranged when cool to engagewith the said gear-train to retard the movement thereof against the urgeof the said motor and when heated to distort and retire out of retardingrelationship with respect to the said gear-train, the said movableadjusting-member being movable with respect to the gear-train toselectively determine the temperature at which the said heat-distortableretarding-member will retire out of engagement with the said gear-train;and electrical connecting-means connecting the said synchronous electricmotor and the said heatdistortable retarding-member in series.

2. An electrically-heated and electrically-timed automatic toaster orthe like, including in combination: a food-holder; electricheating-means located adjacent the said food-holder for heating thecontents thereof; an electric switch controlling the supply of currentto the said electric heating-means; a unitary timing-device for con 2trolling the said electric switch and including a frame, a synchronouselectric motor carried by the said frame; ctuating-means for the saidelectric switch and also carried by the said frame, a gear-trainoperatively connecting the said synchronous electric motor to the saidactuatingmeans, a movable adjusting-member pivoted to the said frameadjacent the said gear-train, and a heat-distortable retarding-membercarried by the said adjustingmemher and swingable therewith as well aswith respect thereto and constructed and arranged when cool to engagewith the said gear-train to retard the movement thereof against the urgeof the said motor and when heated to distort and retire out of retardingrelationship with respect to the said gear-train, the said movableadjusting-member being swingable with respect to the gear-train toselectively determine the temperature at which the said heat-distortableretarding-m mber will retire out of engagement with the said gear-train;and electrical connecting-means connecting the said syn- 10 chronouselectric motor and the said heat-distortable retarding-member in series.

ARTHUR B. POOLE. PETER H. MORGANSON.

